/*
 * Copyright 2008-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.broadleafcommerce.common.util.dao;

import java.util.ArrayList;
import java.util.List;

import javax.persistence.Query;

/**
 * 
 * @author jfischer
 *
 */
public class BatchRetrieveDao {
	
	//Default batch read size
	private int inClauseBatchSize = 300;
	
	@SuppressWarnings("unchecked")
	public <T> List<T> batchExecuteReadQuery(Query query, List<?> params, String parameterName) {
		List<T> response = new ArrayList<T>();
		int start = 0;
		while (start < params.size()) {
			List<?> batchParams = params.subList(start, params.size() < inClauseBatchSize ? params.size() : inClauseBatchSize);
			query.setParameter(parameterName, batchParams);
			response.addAll(query.getResultList());
            start += inClauseBatchSize;
		}
		return response;
	}

	public int getInClauseBatchSize() {
		return inClauseBatchSize;
	}

	public void setInClauseBatchSize(int inClauseBatchSize) {
		this.inClauseBatchSize = inClauseBatchSize;
	}
	
}
